So I figured I would share a hardware project that I have been working on.

This project is to convert a PS/2 Mouse for use on a Color Computer. I decided on a micro controller to do the main work load. The chip I decided to use is a ATmega328P DIP with the Arduino UNO R3 bootloader firmware.

So far I have had a few incarnations of the project. I started with trying to use PWM for the analog output, but ran into a few issues with it being read fully stable by the CoCo when used with the Hi-Res software routines.

I then decided to try a breakout board for testing that used a MCP4725 I2C DAC. I ran into problems with these DAC's dying after about 2 hours of use. (*sigh*)

Jim Brain, of RETRO Innovations, suggested I try using a MCP4922 which is a SPI based DIP package DAC.

I changed my hardware design over to use this MCP4922 and changed my Arduino sketch to match the new hardware with a MCP49xx library I found.

So far this project seems to be working with Color Max Deluxe with the Hi-Res software routines and seems to work with the Tandy Radio Shack Hi-Res Interface Adapter as well.

My current hardware layout I have the PS/2 Port (6 PIN mini DIN) for the mouse input. I have two 6 PIN DIN connectors as well which one of them is used for a Joystick Output which is then connected to the CoCo's joystick input. The other 6 PIN DIN is a input port so you can plug a CoCo joystick into it .

So far the joystick input feature is not enabled as I have not gotten around to adding that feature to the Arduino Sketch yet.

That is very cool that you took the plunge to make a cool new hardware device for the CoCo, looking forward to hearing and seeing more of this.I know Jim Brain did a little work on it, and it would be great to see it when completed, put me down for an order

Steve Strowbridge aka The Original Gamer Stevie StrowHost of CoCoTALK! the nation's leading live talk show featuring the Tandy Color Computer

ogsteviestrow wrote:That is very cool that you took the plunge to make a cool new hardware device for the CoCo, looking forward to hearing and seeing more of this.I know Jim Brain did a little work on it, and it would be great to see it when completed, put me down for an order

Yes Jim Brain is indeed making a version of my project and that is probably a good thing. This project I started as mainly a learning experience to see if I could build a hardware project and get it working.

I myself haven't decided if I am going to sell mine though just because I don't really have the resources or the business model setup.

Though once Jim gets his version done I am going to assume he will be selling his version.

I haven't decided yet if I am going to sell my version yet. Jim Brain will probably be selling his version (at least I hope).

What I probably will do is once I get my project done I will try to make the schematic, board layout, and Arduino Sketch available for download so people can make their own if they so desire. I might try using GitHub for that, but we will see.

I managed to update the Arduino Sketch to now use the Joystick Input that is on the projects board. So far it seems to work. Right now using the PS/2 Mouse's scroll wheel button to toggle between PS/2 Mouse Mode and Joystick Pass Through Mode.